There is a granular product called Preen, which is really just Corn Gluten. You can also find bags of Corn Gluten at a feed store or Farm store.
Corn Gluten will stop the ANNUAL weed seeds from germinating, but doesn’t effect PERENNIAL weeds, which you will need to dig out by hand, or selectively blast with an herbicide.
If anyone solves this common problem, they will own the world!
The active ingredient in Preen is trifluralin, ie: Treflan
It is a pre-emerge herbicide that is quite toxic to fish and aquatic invertibrates, and is known to be an endocrine disrupter in mammals. Corn gluten is not a component of Preen, but it does use ground corn cob as the carrier material for the active ingredient.
I’ll use Preen on Mrs. Augie’s flower beds, but I don’t want it anywhere near my victory garden.
I hate pulling weeds, so I may pick up some corn gluten this spring and give that a try.